Help adding winni to end of cycle

I am in week 7 of a 12 week test-c 500mg a week cycle and everything is going great. Strength is up, size is up, and feeling great. I recently got offered 20 tabs of stanozolol and was thinking I could throw them in at the end of my cycle. I know the half life on winni is short, so I was wondering do I run it the last 3 weeks of the cycle while I'm still injecting or run the last two weeks then the first week of the two week break before my pct? Hope this makes sense any help is appreciated!